What is JotForm?
JotForm is a free online form builder which helps you create online forms without writing a single line of code. No sign-up required.

At JotForm, we want to make sure that you’re getting the online form builder help that you need. Our friendly customer support team is available 24/7.

We believe that if one user has a question, there could be more users who may have the same question. This is why many of our support forum threads are public and available to be searched and viewed. If you’d like help immediately, feel free to search for a similar question, or submit your question or concern.

  • Profile Image

    Adding Input Mask makes phone number field too small on mobile

    Asked by SOLDIERFITSterling on December 30, 2016 at 09:23 PM

    After adding the input mask and validation so my customers can only put in numbers and at least 10 in the field the field is too small to read what was put in when looking at on a mobile device. I assume this has something to do with mobile responsiveness as the field is fine on a computer. I've tried changing the width of the field with custom CSS code but to no avail.

    Page URL:

  • Profile Image
    JotForm Support

    Answered by BJoanna on December 31, 2016 at 07:13 AM

    I have tested your form and I was able to replicate mentioned issue. 

    Please add this CSS code to your form:

    [data-type="control_phone"] .form-sub-label-container:first-child {

        width: 100%!important;


    How to Inject Custom CSS Codes


    After that you form should look like this on mobile devices.

    Here is my cloned form with mentioned CSS code:


    Feel free to test it and clone it.

    Hope this will help. Let us know if you need further assistance.

  • Profile Image

    Answered by SOLDIERFITSterling on December 31, 2016 at 03:55 PM

    That worked perfectly! Thank you!